Chain wrench



sin. 27, 1927.;

c. .1. REWEII'T CHAIN WRENCH F iled Feb. 16, 1924 I I l a W W! avers Q Patented Sept. 27, 1927.

warren STATES- CARL J. REWETT, OFLOS ANGELES, CALIFORNIA.

CHAIN WRENCH.

Application filed. February is, 1924.

power and are required to have great strength and tight grip. and yet are required to hold the casing in such a man ner that they will not'crush. cut, or scar the casing.

In the operation of screwing the joints of easing together or unscrewing them apart the power is applied from an engine with tremendous force and with a. jerk, and it is very dangerous for the wrench to slip on the casin g -itor when such slipping occurs the lever is likely to cripple or kill the operator.

' An object of this invention is to provide a chain wrench. which will not slip on the casing, and will not crush; cutr crimp, or scar the casing.

Such wrenches" are swung from a block with chains that are fastened to one side of thclever. Chain wrenches will only take holdin one direction. and hold one joint of the chain wrench' while another joint of the casing" is being screwe or unscrewed therefrom. i v

Sometimeshowever, a casing maybe put down or pulled when only one wrench is available, and then it becomes necessary to turn the wrench invention is to enable the operator to allow the wrench lever to remain with one edge or side up under all conditions and the change from right to left be accomplished bysimply changing the chain orjointed member.

ltalso sometimes occurs that during open ation the pins or pivot bolts that hinge t'oge-ther the joints of? the chain will be broken and it is then necessary to removetlie'broken pin and to replace it with new.

An object ofthis invention is to enable the operator to readily takeout and'replace any of the pins or bolts which hinge the l nembers together and this "I accomplish by con structing the pinswith ends reduced to'form shoulders that are flush with the'sides ofthe members, through which the pin is inserted. and the outer radius ends of suchpins are threaded to receive nuts that are supportedby both the shoulder and the link of the chain whensaid nuts are tightly screwedhome. By providing a=threadedportion at it is customary to over and an object orthis Serial No. 693,230.

each end of'thc bolt or pin it is possible to remove the pin in either direction from the wrench, thus in many instances facilitating the work.

A feature ofinvention is'shown in the hinged tail or toe that is arranged at the end of the links so that it can be wedged between the links and a pipe when the wrench is in use.

Other objects, advantages and features of invention may appear from the accompanying drawing. the subjoined detailed description and the appended claims.

The accompanying drawing; illustrates the invention.

Fig. 1: is aside elevation of the applianceon a small scale constructed in accordance with this invention; and showing it in use supported by a cable and lifting a well casmg.

Fig; 2 is view'on lin'e m -m 1 with the wrench turned opposite to its position shown in Fig; 1.

Fig. 3 is a w -m Fig; 2.

fragmenta'l section" on line the pipe as arranged in Fig. 2. I

. Fig. 6 is an enlarged detailed view of one of the link bearing pins connecting'two of the links. afragment of which is shown in section. 7

Fig. 7 is a detailed view illustrating the rigid connection between the connecting block'and lifting beam. with a fragment of the latter shown in section.

The wrench comprises a. gripping member l towhich a'leverage lifting beam 2 ispivotally connected. 7 v

The leverage lifting beam 2 and the connecting' block 3 of the gripping member 1 are rigidly connected" together by a. bearing pin 4. Y

The connecting block 3 is of unitary construction and'bit'urcated to provide a recess wand to f'orm the arms 3'. 3" which straddle the beam Qand to which the beam is connected. The beam is snugly fitted into the recess a to form a rigid connection at 5, 5' to receive the reduced end of the link 6 that is pivotally connected to the block 3 by the eye'bolt 7 The link'6 is pivotally connected to link 8 by a pin 9; and link 10 is connected to link 8 by a pin 11; and these links are of greater width than length; and they are slightly curved so that their inner walls can be fitted to pipes of various diameter.

Link 10 is pivotally connectedto a gear segment 12 by a pin 13; and this segment has on its outer wall the gear teeth 14L that are adapted to be engaged by teeth 241 on the fulcrumed end of beam 2 when the wrench is fitted to a pipe of intermediate or small diameter; and the inner curved wall of the segment is provided with the steel teeth 15 that are adapted to engage the outer wall of a pipe when the wrench is fitted thereto. I

Another gear segment 16 is pivotally connected to the segment 12 by a pin 17 and segment 16 is provided with gear teeth 18 on its outer wall which also are adapted to be engaged by teeth 24 when the wrench is fitted to a pipe of large diameter; and the inner wall is provided with steel teeth 19 that are adapted to engage the outer wall of a pipe when the wrench is fitted thereto.

A tail or toe 20 is pivotally connected to the segment 16 by a pin 21: and this tail is curved and tapered to a point so that it can be easily wedged between. the links 6, 8 or 10 and a pipe 25 to hold the wrench from slipping or sliding on a pipe when in use. I

The segments 12, 16 are provided with sockets 22 in which the hardened steel. teeth 15, 19 are seated: and the teeth are arranged so that a sharp edge of each extends slightly outward beyond the inner curved walls of the segments in position to engage and be embedded in the wall of a pipe when tension is applied to grip the segments thereto.

Tension is applied to grip the segments, links and tail around the pipe 25 by means of the beam 2 that has its fulcrum end provided with teeth 24 that as heretofore stated are adapted to engage the gear teeth 14 or 18: which. when so engaged and leverage is applied. to the beam to force the chain of links. segments and tail toward and around a pipe the wrench can be gripped thereto with great force without crushing the pipe so that v a dog 27 on the segment tension'is applied to the beam it will hold and not slip or loosen when the pine is handled.

A fter tension is applied to grip the wrench to the pipe 25 it is locked thereon by means of chain 26 and dog 27.

lhe chain has one end thereof secured to aneve bolt 28 in the block 3: and the links thereof are formed to engage and be held by 12. That is. when 2 to firmly engage the wrench with a. pipe 25, a link of the rhain 26 is caught over the dog 27 so that it holds the wrench securely locked to the pipe.

To facilitate the handling of the heavy wrench I provide suspending rods 29 that have their lower ends secured to the eye shown, the

bolts 30, 31 and the upper ends of the rods 7 cable 35, a fragment of which is shown in Fig. 1. As seen therein the wrench is attached to a well casing 25 so that when the cable 35 is actuated upward by a derrick, not pipe will be drawn from the ground 35. V

By means of the fore wrench can be raised and lowered and swung to various positions by mechanical power.

Also to facilitate engaging the wrench with a pipe, a handle 36 is pivotally connected to thebearing pin 13 and arranged so that" it can be used to move the links and segments on their hearing pins.

going support the The pin 4, eye bolt 7 and pins 9, 11, 13,

17, 21 are preferably formed of'tool steel so that they will easily resist shearing and breaking strains to which they are subjected in handling heavy casings. I

The pins are preferably formed of a uniform diameter throughout the joints as shown in detail in Fig. 6; and they have threaded reduced ends'37 on which are fitted the retaining nuts 38 that are secured thereon by the cotter pins 39.

In operation, the wrench is preferably moved by mechanical power into position toengage a well casing to which it is to be attached; and at which time ments and tail are in open position.

Then by manual means the links, segments and tail are moved on their pivot pins to encircle the casing, in which position the steel teeth 15. 19 of the segments 12, 16 engage the casing and the tail 20 is wedged between one of the links 6, 8 or 10 and the casing, and in this position the teeth 24 of beam 2 are in position to engage the teeth of either the segment 12 or 16 so that tension canbe applied to grip the wrench to the casing so thatit cannot slip or turn. It can then be locked to scribed.

By the construction, combination and arrangement of the various parts I provide a strong and durable wrench having a gripping surface of large area so that great force can be applied to secure it to a casing withou crushing it.

I claim:

1. The wrench set forth comprising a leverage lifting beam having gear teeth on its fulcrumed end; and a gripping member adapted to grip a well casing, said member comprising a connecting block having arms straddling said beam and being connected thereto; links pivotally connected together and to said block; gear segments pivotally connected together and to said links and being provided on their inner surfaces with teeth to engage said casing and on their outer surfaces with gear teeth adapted to be the casing as previously de-' the links, se'gengaged by the teeth on said beam; and a toe at the free end of said gear segments adapted to be wedged between said links and well casing. V

2. The wrench set forth comprising a leverage lifting beam having gear teeth on its fulcrumed end; and a gripping member adapted to grip a well casing, said member comprising a connecting block having arms straddling said beam and being connected thereto; links pivotally connected together and to said block; gear segments pivotally connected together and to said links and being provided on their inner surfaces with teeth to engage said casing and on their outer surfaces with gear teeth adapted to be engaged by the teeth on said beam; a toe at the free end of said gear segments adapted to be wedged between said links and well casing; and a chain secured to the gripping member and adapted for detachable connection to one of the gear segments for locking the wrench in position upon the casing.

3. The wrench set forth comprising a leverage lifting beam having gear teeth on its fulcrumed end; and a gripping member adapted to grip a well casing, said member comprising a connecting block having arms straddling said beam and connected thereto ;links pivotally connected together and to said block; gear segments pivotally connected together and to said links, said gear segments being provided with teeth on their inner surfaces adapted for engagement with said casing and having gear teeth provided 011 their outer surfaces adapted to be engaged by the teeth on said beam; a toe element pivotally connected to the free end of one of said gear elements adapted to be wedged between one of said links and the well casing; an eye-bolt secured to said gripping member; a dog formed on one of the gear segments; and a chain connected at one end to said eye-bolt and having link engagement with said dog for holding the wrench in position upon the casing. In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 2nd day of February, 1924. 1

' 1 CARL J. BEWVETT. 

